Gamma knife radiosurgery for multiple brain metastases from non-small cell lung cancer - Comparison with whole brain radiation therapy

Abstract

Objective: The purpose of this retrospective study is to compare the effectiveness of gamma knife radiosurgery (GKS) with that of whole-brain radiation therapy (WBRT) for multiple cerebral metastases from non-small cell lung cancer. Study Design: Among 302 cases with cerebral metastases from non-small cell lung cancer treated at the Chiba Cardiovascular Center and Chiba Cancer Center between 1990 and 1999, 100 consecutive patients filling the following 4 entry criteria were analyzed in this study: 1) Up to 10 multiple brain lesions at initial MRI study; 2) No surgically inaccessible tumors with more than 30 mm in diameter; 3) No carcinomatous meningitis; 4) More than 3 months of life expectancy. The patients were divided into two groups: the GKS group (66 patients) and the WBRT group (34 patients). In the GKS group, large lesions (≥30mm) were removed microsurgically and all other small lesions (<30mm) were treated by GKS. New distant lesions were treated by repeated GKS without prophylactic WBRT. In the WBRT group, the patients were treated by the traditional combined therapy of WBRT and surgery. In both groups, chemotherapy was administered according to the primary physician's protocol. Results: The two groups did not differ in terms of age, gender, initial Karnofsky Performance Scale (KPS) score, pathology of lung cancer, number, and size of brain lesion, systemic control, and chemotherapy. Overall survival (OS), neurological survival (NS) and qualitative survival (QS) of the GKS group were longer than those of the WBRT group according to Kaplan-Meier's method. In a multivariate analysis the WBRT group also had significant poor prognostic factors for OS, NS and QS. Conclusions: GKS without prophylactic WBRT could be a primary choice of treatment method for patients with as many as 10 cerebral metastases from non-small cell lung cancer.